Apparatus for forming porous beds of finely divided material



Sept. 19,1944. G. K. WILLIAMS 2, 8 4

APPARATUS FOR FQRMING POROUS BEDS OE FINELY DIVIDED MATERIAL I Filed Aug. 5, 1943- ZCEO 30 a, a

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0 Zawms MAM Patented Sept. 19, 19 14 7 APPARATUS FOR FORMING. POROUS BEDS OF FINELY DIVIDED MATERIAL George Kenneth Williams, Port. Pirie, South Australia, Australia.

Application August 5, 1943,':Serial No. 497,502

In, Australia July 21, 1942 14 Claims.. (o1. ass-20 L This invention relates to. improvementsin. and connected with apparatus for roasting and/or sintering ores and other finely divided materials, such apparatus being of the blast type in which air is caused to pass through the bed as distinguished from apparatus in which air is passed over the bed. The invention has been devised primarily for application to machines of. the wellknown straight line Dwight-Lloyd type, but is not limited thereto as it is equally applicable to circular and other types of blast roasting and/ or sintering machines.

In order that the roasting operation may b performed with a high degree of efficiency, the ore bed should be of uniform texture and of such porosity as to permit of free contact of the constituent particles thereof with the air drawn therethrough. With this end in view many at-- tempts have heretofore been mad to control the initial formation of the ore bed in such a manner as to ensure a requisitedegree of porosity and obviate irregularities in the texture of density thereof. In general, however, it has been found that, notwithstanding the attempts referred to, the portions of the bed disposed adjacent to the sides thereof have been more readily roasted than the central portions thereof. This disadvantageis accentuated when the width of the bed is: in creased and infact has heretofore imposed a limit on the practicable width of the bed.

Now the object of this invention is toprovide an improved method of and apparatus for form-; ing an ore bed in roasting and like apparatus whereby the roasting or other operation may: be performed more efiiciently and/or whereby a bed. of greater width than has heretofore. been prac ticable, may b successfully employed.

With these objects in view one broad feature of the invention resides inmechanically conditioning the bed of finely divided material after the initial formation thereof and prior to the commencement of the treatment operation, e. g. roasting. For this purpose the bed is preferably subjected after its initial formation and prior to the roasting thereof, to the action of deflecting means located below the free surface of the bed, such means preferably being arranged to extend substantially across the full width of the bed.

Apparatus in accordance with the invention,

broadly comprises conditioning means located.

below the free surface of th bed behind the feeding means therefor, said conditioning means serving to subject the ore bed to vertical move.- ment as said bed is moved forwardly.

ably mounted whereby it may be automatically displaced to permit of the passage of solid. bodies present in the bed... 7 '1 More particularly the apparatus preferably in corporates a plurality of. transversely disposed A members arranged substantially horizontally somewhat above the bottom of the bed and in Preferably the said conditioningmeans is mov- I different transverse sections thereof the upper faces of said members being inclined upwardly in th direction of movement of the bed whereby. during its forward. movement, the upper portion thereof will move upwardly over said members and will then again descend to reform a relatively uniform and porous bed.

Each transverse member may be secured to the lower end of a pivoted jump arm having means associated therewith to resist, displacement thereof. Stop means, which may be adjustable, are preferably provided for limiting the downward movement of said transverse members.

The apparatus also preferably incorporates means for re-levelling the upper surface of the bed after the aforesaid conditioning operation has been performed thereon, said relevelling means preferably comprising a transverse levelling member arranged to rest lightly upon the upper surface of the bed; said levelling member being preferably arranged to float whereby it will freely adapt itself to variations in the thickness or depth of the bed.

Other objects and features of the invention are hereinafter described.

Inthe accompanying drawing, which illustrates one practical embodiment of the invention:

Figure l is a view inside elevation of a straightline Dwight-Lloyd type of ore roasting machin and indicates the location of bed re-forming and re-levelling apparatus in accordance with the invention.

Figure 2' is a View in longitudinal section through a portion of the roasting machine adjacent said bed reforming and re-levelling apparatus and is drawn to a larger scale.

Figure 3 is a view in plan of the portion ofthe apparatus shown-in Figure 2, the centerline of the machine being indicated by a broken line.

Figure 4 is an isometric view showing one of the bed re-forming members and portions of the corresponding adjacent members;

Figure 5 is a view in end elevation andpartly in section of the bed-relevelling means; ,and

Figure 6 is an isometricview showing one end of the .bed re-levelling means. or

Referring now to Figure 1, the fram generally designated l5] supports pallet tracks H and I2, the upper track ll being arranged horizontally while the lower track [-2 inclines downwardly from the discharge end l3 of the machine to the free end [4 thereof whereby the palletsv I5 will gravitate therealong after discharging their contents into the hopper l6.

At the feed end of the tracks H and 12 are extendedby concentric arcuate tracks It and i2" which are spaced from each other to enable the rollers H of the pallets to pass therebetween as said pallets are successively raised in the direction of the arrow.

Each pallet I5 is open at the front and back while the bottom thereof is formed by fire bars i9 arranged between upstanding end plates 20.

Those pallets, which at any time are located on the upper pallet track I I, are disposed in contact with each other and thus form a relatively shallow trough which extends uninterruptedly for substantially the full length of the machine, the sides of this trough being formed by the end plates of the pallets.

A charging hopper 2| is located transversely above the feed end of the machine and an endless conveyor 22 therein continuously discharges, into the aforesaid trough, the material to be treated, whereby a bed 23 of predetermined depth is formed therein.

This bed is carried forwardly by the pallets below ignition boxes 24 and above a series of exhaust chambers 25 whereby the roasting operation is initiated and then maintained until the pallets successively reach a predetermined position adjacent to the discharge end of the machine.

The apparatus as so far described is well known and does not form a part of the present invention.

Now, for the purpose of the present invention, a series of deflector bars 26 arranged in end-toend relationship extend transversely of the machine between the charging hopper 2! and the ignition box 24. These deflector bars in the illustrated embodiment are of rectangular shape in cross section and incline upwardly and forwardlyi. e. in the direction of movement of the ore bed, and are disposed Wholly below the upper surface of the bed 23 as shown in Figure 2.

Each deflector bar 26 is mounted on the lower end of a depending arm 21 of a corresponding bell crank lever, the several bell crank levers being pivoted at spaced intervals to brackets 28 secured to the main frame (Figure 4). The other arm 30 of each bell crank lever extends forwardly (i. e. in the direction of movement of the bed) above and in contact with a stop member 3| fitted to a fixed beam 32 and is provided at its free end with weights 33 for exerting a downward pressure thereon though springs may be used in lieu thereof if desired.

The beam 32 also extends transversely above the ore bed and is secured to the main frame In by members 34.

It will be evident that, as the deflector bars 26 are located within the ore bed, the pressure exerted thereon by the moving bed tends to carry them forwardly, but this tendency is resisted by the downward pressure exerted on the forwardly extending arms 30 of the bell crank levers by the weights 33.

Thus in normal operation the material forming the upper portion of the bed moves forwardly and upwardly over the deflector bars 26 as shown in Figure 2 and. then falls through a small distance from the upper and rear edges thereof whereby the bed is loosened and then re-formed in a substantially loose and uniformly porous condition.

If, however, any of the deflector bars encounters any solid body or other obstruction, it is caused thereby to swing forwardly and upwardly in opposition to the associated weight 33 as shown by broken lines in Figure 2 to permit said body to pass therebelow without imposing an undue strain on the apparatus after which the displaced deflector bar returns to its normal position, which is determined by the stop member 3|. For this purpose the deflector bars 26 preferably are normally disposed approximately vertically below the pivotal axes of the respective bell crank levers as shown.

Thesurface of the bed is re-levelled after the completion of the foregoing operation by means of a levelling bar 35 Of angle cross section, which extends transversely of the machine above the ore bed and between the deflector bars 26 and the ignition boxes 24. Each end of this bar 25 is fitted with a plate 36 which rotatively supports a pair of rollers 31 engaging an inclined track 38 pivoted at 39 to a fixed member 40 and retained in a suitable position of adjustment by a screwed rod 4| (see Figures 5 and 6). The weight of the bar 35 is partly counterbalanced by weights 42 attached to the free end of cables 43 extending around rollers 44 each cable having its opposite end secured to the adjacent end of the levelling bar. The levelling bar is indicated in Figure 1 but the supporting means therefor are omitted from this figure.

Thus the levelling bar 35 is free to move in an upwardly and forwardly inclined path which is parallel to the inclined tracks 38. Upward movement is, however, resisted by the unbalanced weight of the bar and coacting parts while downward movement is resisted by the pressure exerted on the bar by the ore bed 23. Consequently the height of the bar is automatically regulated whereby the upper surface of the bed is levelled without consolidating the material therein.

If desired, the levelling bar 35 ma be formed in a plurality of independent coaxially aligned transverse sections similarly to the deflecting means 26, though a continuous bar as shown has given quite satisfactory results. It will also be evident that springs may be used in lieu of the weights 42.

Apparatus constructed and arranged as hereinbefore described results in the formation of an ore bed which is substantially, uniform and of a suitable degree of porosity across the full width thereof with the result that an increase in roasting efliciency is obtained while furthermore the expense and complication of special ore feeding means has been obviated.

'By means of this invention it has also been found practicable to operate successfully a roasting machine with a substantially wider bed than has heretofore been possible.

Iclai-m:

1. Apparatus for conditioning a moving bed of finely divided material comprising a travelling support, means for distributing finely divided material on said support to form a bed thereon and means located below the free surface of the initially formed bed to progressively displace the material forming at least the upper portion of the bed as the latter moves forwardly.

2. Apparatus for conditioning a moving bed of finely divided material comprising a moving support, means for distributin finelydivided mathereof whereby the material forming at least the upper layer of said bed will move progressively upwardly thereover and then downwardly therebehind during the forward movement of the bed.

4. Apparatus for conditioning a moving bed of finely divided material comprising a travelling support, means for distributing finely divided material on said travelling support to form a bed thereon, and deflecting means extending transversely of said bed and substantially for the full width thereof behind said distributing means, said deflecting means being arranged below the surface of the bed and being inclined upwardly and forwardly in the direction of movement of the bed whereby the material forming the upper portion of said bed will pass progressively upwardly over said deflecting means.

5. Apparatus for conditioning a moving bed of finely divided material comprising a travelling support means for distributing finely divided material on said support to form a bed thereon and a plurality of deflecting means arranged substantially transversely below the surface of said bed and substantiall in different transverse sections thereof, some at least of said deflecting means being inclined upwardly and forwardly in the direction of movement of the bed whereby the material forming at least the upper layer thereof will progressively move upwardly over said deflecting members and downwardly therebehind.

6. Apparatus for conditioning a moving bed of finely divided material and according to claim wherein said deflecting means are arranged in transverse alignment.

'7. Apparatus for conditioning a moving bed of finely divided material comprising a travelling support means terial on said support, a plurality of deflecting members arranged substantially transversely below the surface of the bed and substantially in different transverse sections thereof and means movably supporting each said deflecting member to permit of its being displaced by obstructing bodies in the bed.

8. Apparatus for conditioning a moving bed of for distributing finely divided ma-.

finely divided material comprising a travelling,

support means for distributing finely divided material on said support, a plurality of deflecting members arranged substantially transversely below the surface of the bed and substantially in different transverse sections thereof and means pivotally supporting each said deflecting member about a substantially horizontal axis disposed substantially vertically above said deflecting member.

9. Apparatus for conditioning a moving bed of finely divided material comprising a travelling support, means for distributing finely divided material on said travelling support to form a bed thereon, a plurality of depending pivoted arms spaced transversely of the bed, a series of deflecting members arranged substantially horizontally in end-to-end relationship and extending transversely below the surface of the initially formed bed for substantially the full width thereof, each deflecting member being mounted on the lower end of one of said depending pivoted arms, stop means for limiting movement of each deflecting member in one direction and means exerting pressure on each of said depending pivoted arms to resist movement of the respective deflecting members in the opposite direction.

10. Apparatus for conditioning a moving bed of finely divided material and according to claim 9 comprising a laterally extending weighted arm secured to an upper portion of each depending pivoted arm to resist displacement in one direction of the respective deflecting member.

11. Apparatus for conditioning a moving bed of finely divided material comprising a travelling support, means for distributing finely divided material on said support to form a bed thereon, means extending below the free surface of the initially formed bed to progressively displace the material forming at least the upper portion of the bed, as the latter moves forwardly and means located behind said displacing means tore-level the surface of the bed.

12. Apparatus for conditioning a moving bed of finely divided material comprising a travelling support means for distributing finely divided material on said travelling support to form a bed thereon, deflecting means extending transversely of said bed and substantially for the full width thereof behind said distributing means, said deflecting means being arranged below the surface of the bed and being inclined upwardly and forwardly in the direction of movement of the bed whereby the material forming the upper portion of said bed will pass progressively upwards over said deflecting means, transversely disposed means arranged behind said deflecting means to re-level the surface of the bed and means movably supporting said re-leveling means to permit of rising and falling movements thereof.

13. Apparatus for conditioning a moving bed of finely divided material comprising a travelling support means for distributing finely divided material on said support to form a bed thereon, a plurality of deflecting means arranged substantially transversely below the surface of said bed and substantially in different transverse sections thereof, some at least of said deflecting means being inclined upwardly and forwardly in the direction of movement of the bed whereby the ma terial forming at least the upper layer thereof will progressively move upwardly over said deflecting members and downwardly therebehind, a movable re-levelling member arranged transversely above the bed and behind said deflecting means and upwardly and forwardly inclined guides for said re-levelling member.

14. Apparatus. for conditioning a moving bed of finely divided material comprising a travelling support means for distributing finely divided material on said support to form a bed thereon, a

. plurality of deflecting means arranged substantially transversely below the surface of said bed and substantially in different transverse sections thereof, some at least of said deflecting means being inclined upwardly and forwardly in the direction of movement of the bed whereby the material forming at least the upper layer thereof will progressively move upwardly over said deflecting members and downwardly therebehind, a vertically and horizontally movable re-levelling member arranged transversely above the bed and behind said deflecting means, upwardly and forwardly inclined guides for said re-levelling member and -means partly counterbalancing the weight of said re-levelling member.

GEORGE KENNETH WILLIAMS. 

